The invention relates to a device for affixing objects to products moving in a row, which device is provided with a holder for a stock of said objects and with affixing means comprising a carrier for removing an object from said holder and moving said object, and which affixing means are capable of rotary movement about an axis of rotation and of affixing said object to the moving product during said rotary movement.
A device of this kind can for example be used for placing objects, such as product samples, in a magazine. For example, bags of shampoo or bags of soup can be glued to a particular page of a magazine. This can be done when quires of said magazines are joined on a binding machine, whereby said quires move along in a row.
The device may also be used for affixing address labels or other appendices to parcels, for example, before said parcels are enveloped in transparent plastic material.
The device may for example also be used for providing flat sheets, from which a packaging box is to be formed, with stiffening parts which are glued to said flat sheet to form a stiffening element in the box when it is folded at a later stage.
With such a device, it is important that the occurrence of malfunctions is reduced to a minimum, because the affixation of objects by means of such a device forms part of a comprehensive, continuous process, which process can be stopped entirely by a malfunction. Generally, such a device is only suitable for affixing one particular type of object.
The objective of the invention is to provide a device for affixing objects to products moving in a row, wherein different kinds of objects, in particular objects having a three-dimensional shape of other objects which are difficult to handle, can be affixed at a high rate in a reliable manner.
To this end, the affixing means can be driven intermittently, with rotation and standstill alternating with each other, during which standstill the carrier can remove an object from the holder. The temporary standstill of the affixing means enables the carrier to remove an object from the holler in a reliable manner, whilst the rotary movement of the affixing means causes the carrier to move in a circular arc, which is a suitable movement for affixing the objects being taken to products moving in a rectilinear path.
Preferably, the affixing means are provided with more than one carrier, three carriers in a preferred embodiment, wherein the carriers are positioned a substantially uniform distance apart in a circle round the axis of rotation, in such a manner that one carrier is positioned near the holder during standstill of the affixing means, whilst the place where the objects are to be affixed to the products is located at a position on said circle, substantially centrally between two carriers. When three carriers are provided, the carrier which is positioned straight above the affixing means during standstill of the driving means can pull objects from a holder at the underside thereof, whilst a carrier which moves in a circular path, during which movement it can affix an object to a moving product, will be present at the underside of the affixing means during the rotation of the driving means that is carried out in order to place the next carrier in the upper position. It is also possible to place the holder in a position other than straight above the affixing means.
Preferably, a carrier is provided with a suction nozzle, preferably two suction nozzles, for engaging an object. Since the affixing means are at a standstill while said engaging takes place, a sub-atmospheric pressure can be generated in said suction nozzle whilst the object abuts against the nozzle at rest. As soon as a desired sub-atmospheric pressure is available, the object can be pulled from the holder and the affixing means can start to rotate. By making the diameter of the suction nozzle sufficiently large, preferably more than 15 mm, a relatively large engaging force can be effected in a relatively short period. The use of two suction nozzles positioned next to one another makes it possible to effect a very stable engagement.
Preferably, the carrier is movable in a radial direction with respect to the axis of rotation, so that the carrier can move during standstill of the affixing means, to a position in which it abuts against an object which is present in the holder, from which position it can pull said object from the holder when the carrier moves in a reverse direction.
In one preferred embodiment, the affixing means are provided with more than one carrier, wherein said carriers are positioned a substantially uniform distance apart in a circle round the axis of rotation, wherein the holder on the one hand and the place where the objects are affixed to the products on the other hand are positioned in such a manner with respect to each other, that one carrier will be present at the location of the holder during standstill of the affixing means, and another carrier, which has removed an object from the holder, will not have affixed said object yet.
Furthermore, a glue dispenser may be present, which is capable of applying an amount of glue to the object which has been engaged by a carrier. The object can then be glued to the product. Especially if the glue is to be applied in a specific manner, for example in order to glue the object to the product in a specific manner, it will be advantageous to apply the glue during standstill of the carrier with the object, which can take place whilst another carrier is engaging an object.
During standstill of the affixing means, an object which has been engaged by a carrier can furthermore be provided with a text, a number or other mark or code, for example by means of an inkjet printer. The encoding of objects in this manner may be considered to constitute an invention by itself.
Preferably, the device is provided with its own electric up; driving motor, and it is preferred not to have the device driven by the same driving means that move the products.
This makes it possible to use the device in a flexible manner, in particular with regard to the location at which the device is installed. Preferably, the rotational speed of the driving motor is controlled on the basis of signals from a pulse generator, which signals are a measure for the speed of movement of the products. Such a pulse generator can be mounted near a rotary shaft of the driving means that move the products, wherein the pulse generator delivers signals which are a measure for the rotational speed of the shaft in question. The rotational speed of the driving motor can be adapted to the speed of movement of the products as desired via electronic control of the driving motor. Thus it is ensured that the rotation of the affixing means and the movement of the products take place in a synchronized manner.
In one preferred embodiment, control means are present, which are capable of putting a carrier temporarily out of action, so that said carrier will not engage an object from the holder during standstill at the holder. This makes it possible to select whether or not to affix an object to a product, for example when a product is missing in the row of moving products, without interfering with the movement of the affixing means.
In another embodiment, control means are present, which control means are provided with detection means, which detect that a moving product is approaching the affixing means. The rotation of the affixing means can be controlled in such a manner that a rotation is started when a product is approaching, whilst the approach of a next product is awaited during standstill.
By using the device it becomes possible to control and/or adjust the speed of motion of the object during rotation on the one hand and the time span between two successive affixing moments of an object on the other hand independently of each other.
In one preferred embodiment, the affixing means are driven via an index mechanism, whose outgoing shaft is intermittently stationary, whilst the ingoing shaft rotates continuously. Such an index mechanism, which is known per se, is commercially available. Preferably, the ingoing shaft of the index mechanism also drives a driving mechanism for driving parts of the device, for example the carrier, during standstill of the affixing means, so that the carrier can move during standstill off said outgoing shaft. Thus, the movement of the carrier can take place at precisely the right moment during standstill of the affixing means.
To that end, the ingoing shaft of the index mechanism is preferably provided with a cam disc, against which a cam abuts, which cam is provided on a driving mechanism for driving parts of the carrier during standstill of the affixing means. The cam may be provided on a lever which is rotatable about a shaft, whereby rotation of said shaft causes the carrier to move.
Preferably, said driving mechanism comprises a lever which is rotatable about a shaft, which lever is provided with a cam, whose movement causes the carrier to move.
The invention furthermore relates to a method for affixing objects to products moving in a row, whereby an object is removed by affixing means from a holder of a stock of objects and subsequently moved by said affixing means to a position in which it abuts against a moving product, whilst the affixing means are rotated about an axis of rotation, at such a speed that the speed of movement of the object is substantially equal to the speed of movement of the product, wherein the affixing means are driven intermittently, with rotation and standstill alternating with each other, during which standstill the affixing means remove an object from the holder. The speed at which said affixation takes place is higher than 5,000 objects per hour thereby, preferably higher than 10,000 objects per hour.
The affixing means can thereby be driven via an index mechanism, the outgoing shaft of which is intermittently stationary, whilst the ingoing shaft rotates continuously, wherein said ingoing shaft can also drive a driving mechanism, which drives parts of the device, for example the carrier, during standstill of the affixing means.
In order to provide a better understanding of the invention, an embodiment of a device for affixing objects to moving products will be described hereafter with reference to the drawings.